1. Field of the Invention
This invention relates to the production of an article comprising a cemented diamond mass bonded to a body of silicon-silicon carbide composite material. Heretofore, processes for the preparation of a cemented diamond mass bonded to a high strength substrate such as silicon nitride (U.S. Pat. No. 4,173,614--Lee et al.) or silicon carbide (U.S. Pat. No. 4,241,135--Lee et al.) utilizing pressures below the pressure of the diamond stable region have required, in addition to the diamond fines, both a body of the high strength substrate material and a separate source of binder material (i.e., eutectiferous silicon-rich alloy) for infiltration through the interstices between the diamond fines. The above-noted patents are incorporated by reference.
2. Summary of the Invention
In accordance with the inventive concept disclosed herein, an integrated article comprising cemented diamond fines bonded to a body of silicon-silicon carbide is produced by a process in which a body of silicon-silicon carbide composite is relied upon both as a source of silicon and to provide for the structural stability of the resulting article. More particularly, it has been discovered that by employing a silicon-silicon carbide composite body as the structural substrate for, or as high strength containment for, the cemented diamond fines, silicon can be squeezed out of the composite by subjecting it to sufficient pressure while it is heated above the melting point of silicon. Silicon-silicon carbide composites suitable for the practice of this invention include, by way of example, those made by the infiltration of a confined carbon fiber preform with molten silicon metal (U.S. Pat. No. 4,141,948--Laskow et al.) and similar infiltration products in which particulate inorganic materials substantially unreactive to molten silicon (e.g., boron nitride particles) are also present (U.S. Pat. No. 4,120,731--Hillig et al.). The Laskow et al. and Hillig et al. patents are incorporated by reference. The process of the inventive concept disclosed herein is carried out by providing a quantity of diamond powder adjacent to a silicon-silicon carbide composite in a stabilized geometry in a container and subjecting this stabilized geometry to the simultaneous application of a pressure of a few thousand pounds per square inch and heat to a temperature above 1500.degree. C. in an inert atmosphere.
Objects and the nature and advantages of the instant invention will be apparent to those skilled in the art from the description set forth herein and the accompanying drawings.